Sebastian ziant de febbanti



UNITED STATES PA ENT oEEIoE.

SEBASTIAN ZIANI DE FERRANTI, OF HOLLINWOOD, ENGLAND.

PRODUCTION OF SHELL AND LIKE FORGING-S.

To all whom it may concern:

Be it known that I, SEBASTIAN ZIANI DE FERRANTI, a subject of the King of Great Britain and Ireland, and residing at Hollinwood, in the county of Lancaster, England, have invented certain new and useful Improvements Relating to the Production of Shell and like Forgings, of which the following is a specification.

This invention relates to the production by press forging of shell and like hollow bodies. Such bodies are forged by placing a heated billet within a cylindrical die closed at one end by an ejection disk, and forcing a blunt-nosed mandrel axially into the billet. The forging. is thus eflected by the squirting of the material of the billet outwardly between the mandrel and the die as the mandrel is forced inward.

It is found that the steel dies with cast iron liners which are at present used, become rapidly eroded, the wear and tear being very great. 7 r p This invention consists in a composite die, the outer member of which is adapted to resist the bursting stresses, and the inner memher to resist the erosive stresses, arranged so that the inner member is supported axially to resist compressive stress, and comprising means for imposing an initial axial con1pressive stress on the inner member.

The invention also consists of means for cooling the outer surface of-the composite die by water circulation or the like.

The invention also consists in inclosing the die in a die chamber forming a jacket through which cooling fluid circulates, and in guiding means which retain the die and die chamber co-axial and permit a limited amount of relative axial motion.

The invention further consists in the improved constructions of forging dies hereinafter described.

In carrying this invention into efl'ect in one form as applied by way of example to the forging of shell bodies, I provide an outer die chamber of suitable strength having a central opening large enough to receive the composite die about to be described. This composite die has an outer part more or less cylindrical made of steel or other metal, adapted to resist the bursting stresses produced in the forging operation. A liner or sleeve of metal capable of resisting the erosive stresses (for example, hard cast iron) is housed inside the outer part in such man- 'of the line.

Specification of Letters Patent. Patented J 10, 1919 Application filed March 5, 1919.

Serial No. 280,819.

thereby set up, compressive stresses in the liner and tensile stress in the outer part. The fitting surfaces may be cylindricalor slightly tapered, the liner beingforced into position in a well known manner. The said parts are retained 'in relative position by a ring or nut screwed to the outer part, and which forms an abutment for the outer end For forging shells or'thelike of relatively large diameter,'the said ring may be secured to the outer. part of the die bybolts and nuts or the lik The composite die'is arranged within the die chamber in such a way that the space between the two is effective for air or water cooling of the die. Circulationis arranged for by providing a supply pipe tothe bottom ofthe die chamber, and a discharge pipe from near its top. 1

In order to facilitate the effective cooling of the die, the outer surface of the composite die may be gilled or serrated. I prefer to construct the outer or steel part of the composite die itself 'in a composite form, comprising a cylindrical steel sleeve and a series of steelrings shrunk on toits exterior, preferably with spaces between the rings so that the effectiveness of the cooling is thereby increased. For a similar reason one or both of the contact surfaces "between the steel sleeve and the outer steel rings may be provided with a series of shallow grooves either axial or spiral, through which air or water may circulate.

Within the inner cast iron liner I provide the usual ejection plunger, which practically fits the inside of the sleeve so as to act as the die bottom, against which the plastic material is pressed as the die is being forced inward and the material is be ing squirted outward. During this process very large axial forces are applied to the cast iron liner by friction of the flowing metal, which forces are transmitted to the outer steel part of the die, it may be partly by the frictional contact and partly through the end ring or nut.

In some forms of carrying the invention into effect, I provide for a limited amount of axial movement of the die relative to the die chamber. The die is then free to move upward as the mandrel is being pressed downward into the material of the billet. Less power is then required for forging and less erosive effect is produced on the liner. In such cases a fluid-tight joint like that of a piston ring or the like is made between the lower end of the die and the inner wall of the die chamber. A similar fluid tight joint may be provided near the top of the ,die.

I append drawings illustrating my invention.

In Figures 1 and 2 the composite die is movable axially relative to the die chamber, while in Fig. 3 the composite die is bolted down to the same base to which the .die chamber 1 is fastened.

In Figs. 1 and 2 the outer part 20f the composite die is bored tapered and the cast iron liner is also tapered. In Fig. 3 the bore vof the outer member is practically parallel. The nut 4 screwed on to the outer member retains the liner firmly in position. 5 is the water space to which the supply pipe 6 and discharge pipe 7 are fitted. The steel shell 2 of the composite die has a series of steel rings 9 shrunk on, and in Fig. 1 the steel rings are shown with a series of shallow grooves 10, which permit the cooling water to have direct access to the outer .surface of the cylindrical shell 2. These grooves can easily be formed by drifting the bore of the rings before being shrunk on. The ejection plunger 12 is shown at the bottom of its stroke and in Figs. 1 and 2 the composite die is also shown at the bottom of its stroke relative to the die chamber. A water-tight joint or piston ring 13 is fitted near the lower end ,of the composite die, and a similar j oint ring 14 may be-fitted nearjthe topof thedie.

It will be seen that by this invention .hard metal liners. can'be used next the billet, formed of material having high resistance to erosion at high temperature, and'to crushing and compressive stresses, biit which may be of low tensile strength. Hard cast iron is merely mentioned as an example. Also by making the outer member of the die in'the 1. In an apparatus of the character de-- scribed, a die chamber forming a jacket, a composite die mounted therein consisting of a liner, a sleeve surrounding and supporting the liner, a plurality of rings shrunk on the outer surface of the' sleeve and provided with the plurality of shallow grooves to permit of the circulation ofa cooling medium therethrough.

2. In an apparatus of the character described, a die chamber, a die mounted for axial movement therein and arranged so as to be jacketed by the chamber, fluid tight packing means between the outer surface of the die and the inner surface of the chamber near the upper and lower edges of thedie,

and means for circulating cooling fluid through the jacket.

In an apparatus of the character described, a die chamber forming a jacket, a composite die mounted for axial movement therein including an outer cylindrical sleeve having a slightly tapered bore, a cylindrical liner tapered correspondingly to the bore of the sleeve and arranged therein, retaining means mounted in the inner surface of the sleeve and means for circulatmg a cooling fluid through the jacket near the enlarged end of the bore for clamping the liner, snugly against the bore of the sleeve.

In testimony whereof I have signed my name to this specification.

SEBASTIAN ZIANI 1m FERRA-NTI.

copies of this patent may be obtained for five cents each, by addressing the Commissioner of Iatents,

' -Washington, D. G. 

